UMLS:C0027627 - FACTA Search

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Query: UMLS:C0027627 (metastases)
103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mta1 gene is a recently identified novel candidate metastasis-associated gene. The deduced amino acid sequence contains an src homology-3 domain binding motif, a zinc finger motif and possible phosphorylation sites, suggesting that this gene is involved in signal transduction or regulation of gene expression. The purpose of our study was to examine the mRNA expression levels of the MTA1, the human homologue of the rat mta1 gene in colorectal and gastric carcinomas and thus to evaluate the relevance of the expression of this gene to human carcinoma progression. The expression of MTA1 mRNA in 36 colorectal and 34 gastric carcinoma samples was compared with that in corresponding normal mucosa tissues by semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR) and the results were compared with clinico-pathologic data. A relative overexpression of MTA1 mRNA (tumor/normal ratio > or = 2) was observed in 14 of 36 (38.9%) colorectal carcinomas and 13 of 34 (38.2%) gastric carcinomas. Clinico-pathologic correlations demonstrated that in colorectal carcinomas, tumors overexpressing MTA1 mRNA exhibited a significantly deeper wall invasion and a higher rate of metastasis to lymph nodes, and tended to be at an advanced Dukes' stage with frequent lymphatic involvement. In gastric carcinomas, the tumors overexpressing MTA1 mRNA showed significantly higher rates of serosal invasion and lymph node metastasis and tended to have a higher rate of vascular involvement. Our data suggest that overexpression of the MTA1 gene correlates with tumor invasion and the presence of metastases and that a high expression of MTA1 mRNA may be a potential indicator for assessing the malignant potential of colorectal and gastric carcinomas.
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PMID:Overexpression of the MTA1 gene in gastrointestinal carcinomas: correlation with invasion and metastasis. 929 40

Breast cancer patients usually do not die of their primary cancers; they die of metastatic disease. Thus understanding the progression of breast cancer to the metastatic state and the changes that take place in highly malignant breast cells are important goals that could eventually result in new therapeutic approaches to highly progressive breast disease. Changes in the expression of certain genes or alterations in gene structures and encoded products can result in benign tumour cells progressing to the metastatic state. Experimentally, this has been performed by transferring dominantly acting oncogenes into susceptible cells and then testing the malignant properties of these cells in suitable animal models, but such rapid qualitative changes occur in vivo only rarely, and the natural progression of mammary cells to the metastatic state is thought to occur through a slow stepwise process that can take several years. Some of the slow stepwise changes in mammary cancer progression can be reversible and need not involve dominantly acting oncogenes or tumour suppressor genes, consistent with clinical observations. An important element of the natural progression of mammary tumours to malignancy may be their ability to circumvent microenvironmental controls that regulate growth and cellular diversity, a process that appears to involve mainly quantitative changes in gene expression, resulting in loss of normal cellular regulation. One of the important mechanisms of cellular regulation in epithelial tissues, such as those found in the breast, is mediated by intercellular junctional communication. Alterations in gene expression can result in loss of gap-junctional communication, concomitant with cellular diversification and progression. It is thought that the highly malignant cancer cells that have slowly evolved in vivo with only a few qualitative changes in gene structure have undergone extensive cycles of diversification and the accumulation of several quantitative changes in the expression of various genes that encode products related to malignancy. We have identified some of the genes that are related to progression and metastasis in breast cancer. For example, one of these genes, a novel gene called mta1 (in rodents) or MTA1 (in humans) appears to be involved in mammary cell motility and growth regulation. Thus highly malignant cellular phenotypes can arise rapidly due to specific qualitative changes in critical controlling genes, or more slowly via less critical qualitative genetic changes coupled with other cellular changes, such as loss of intercellular communication, and changes in gene expression, such as in the MTA1 gene, resulting in cellular diversification and ultimately tumour progression to the metastatic state.
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PMID:Breast cancer metastasis-associated genes: role in tumour progression to the metastatic state. 951 27

The morbidity in most cancer patients is not due to their primary cancers; it is due to metastatic disease. Thus understanding the progression of tumors to the metastatic state and the changes that take place in highly malignant cells are important in the development of new therapeutic approaches to diagnose, prognostically assess and treat highly progressive malignancies. Changes in the expression of certain genes or alterations of gene structures and encoded products can result in benign tumor cells progressing to the invasive and metastatic states. This has been shown in the laboratory by transferring dominantly acting oncogenes into susceptible cells and then testing the malignant properties of these cells in vivo. Usually such rapid qualitative changes in malignant state occur only rarely; the natural progression of tumor cells to the invasive or metastatic state occurs through a slow stepwise process of change. Tumor progression, in some instances, can be reversible, involving changes in dominantly acting oncogenes or tumor suppressor genes. The natural progression of tumors to highly malignant states also involves their ability to circumvent host microenvironmental controls that regulate cellular growth and diversity. Quantitative changes in gene expression rather than qualitative changes in gene structure are important in microenvironmental effects on progression. One of the important mechanisms of cellular regulation in epithelial tissues, such as breast epithelium, appears to be mediated by intercellular junctional communication. Changes in gene expression can result in loss of junctional communication, followed by cellular diversification and progression. Highly malignant tumor cells that have slowly evolved in vivo with only a few qualitative changes in gene structure have probably undergone extensive cycles of diversification and have multiple quantitative differences in gene expression. Some of these genes are related to metastasis. For example, we have identified a novel gene called mta1 (rat) or MTA1 (human) that appears to be involved in mammary cell motility and growth regulation. This may be an example of a gene that regulates highly malignant cellular phenotypes. When coupled with other cellular changes, such as loss of intercellular communication, specific changes in gene expression may result in cellular diversification and tumor progression.
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PMID:Metastasis-Associated genes and metastatic tumor progression. 989 Dec 20

Although the expression of the metastases-associated gene MTA1 correlates with tumor metastases, its role in regulating type IV collagenase expression is unknown. Enforced MTA1 expression in HT1080 cells reduced basal and 12-myristate 13-acetate-induced 92-kDa type IV collagenase (MMP-9) protein/mRNA levels. DNase I hypersensitivity and PstI accessibility assays revealed multiple regions of the MMP-9 promoter (-650/-450 and -120/+1), showing reduced hypersensitivity in the MTA1-expressing cells. Chromatin immunoprecipitation assays demonstrated MTA1 binding to the distal region, which spans several regulatory cis elements. Co-immunoprecipitation and chromatin immunoprecipitation assay experiments revealed histone deacetylase 2 (HDAC2)-MTA1 protein-protein interactions and the MTA1-dependent recruitment of HDAC2 to the distal MMP-9 promoter region, yielding diminished histone H3/H4 acetylation. However, HDAC2 binding and H3/H4 acetylation at the proximal MMP-9 region were unaffected by MTA1 expression. Furthermore, trichostatin treatment only partially relieved MTA1-repressed MMP-9 expression, indicating a HDAC-insensitive component possibly involv ing the nucleosome-remodeling Mi2 activity, which was recruited to the promoter by MTA1. In summary, (a) MMP-9 adds to a short list of MTA1-regulated genes, which so far only includes c-myc and pS2, and (b) MTA1 binds to the MMP-9 promoter, thereby repressing expression of this type IV collagenase via histone-dependent and independent mechanisms.
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PMID:Repression of 92-kDa type IV collagenase expression by MTA1 is mediated through direct interactions with the promoter via a mechanism, which is both dependent on and independent of histone deacetylation. 1243 81

Using differential cDNA library screening techniques based on metastatic and nonmetastatic rat mammary adenocarcinoma cell lines, we previously cloned and sequenced the metastasis-associated gene mta1. Using homology to the rat mta1 gene, we cloned the human MTA1 gene and found it to be over-expressed in a variety of human cell lines (breast, ovarian, lung, gastric and colorectal cancer but not melanoma or sarcoma) and cancerous tissues (breast, esophageal, colorectal, gastric and pancreatic cancer). We found a close similarity between the human MTA1 and rat mta1 genes (88% and 96% identities of the nucleotide and predicted amino acid sequences, respectively). Both genes encode novel proteins that contain a proline rich region (SH3-binding motif), a putative zinc finger motif, a leucine zipper motif and 5 copies of the SPXX motif found in gene regulatory proteins. Using Southern blot analysis the MTA1 gene was highly conserved, and using Northern blot analysis MTA1 transcripts were found in virtually all human cell lines (melanoma, breast, cervix and ovarian carcinoma cells and normal breast epithelial cells). However, the expression level of the MTA1 gene in normal breast epithelial cells was approximately 50% of that found in rapidly growing adenocarcinoma and atypical epithelial cell lines. Experimental inhibition of MTA1 protein expression using antisense phosphorothioate oligonucleotides resulted in inhibition of growth and invasion of human MDA-MB-231 breast cancer cells with relatively high MTA1 expression. Furthermore, the MTA1 protein was localized in the nuclei of cells transfected with a mammalian expression vector containing a full-length MTA1 gene. Although some MTA1 protein was found in the cytoplasm, the vast majority of MTA1 protein was localized in the nucleus. Examination of recombinate MTA1 and related MTA2 proteins suggests that MTA1 protein is a histone deacetylase. It also appears to behave like a GATA-element transcription factor, since transfection of a GATA-element reporter into MTA1-expressing cells resulted in 10-20-fold increase in reporter expression over poorly MTA1-expressing cells. Since it was reported that nucleosome remodeling histone deacetylase complex (NuRD complex) involved in chromatin remodeling contains MTA1 protein and a MTA1-related protein (MTA2), we examined NuRD complexes for the presence of MTA1 protein and found an association of this protein with histone deacetylase. The results suggest that the MTA1 protein may serve multiple functions in cellular signaling, chromosome remodeling and transcription processes that are important in the progression, invasion and growth of metastatic epithelial cells.
Clin Exp Metastasis 2003
PMID:Tumor metastasis-associated human MTA1 gene and its MTA1 protein product: role in epithelial cancer cell invasion, proliferation and nuclear regulation. 1265 Jun 3

Metastasis-associated genes (MTAs) represent a rapidly growing novel gene family. At present, there are three different known genes (MTA1, MTA2, and MTA3) and six reported isoforms (MTA1, MTA1s, MTA1-ZG29p, MTA2, MTA3, MTA3L). MTA1, MTA2, and MTA3 are components of the nucleosome remodeling and deacetylation complex, which is associated with adenosine triphosphate-dependent chromatin remodeling and transcriptional regulation. MTA proteins, as a part of the NuRD complex (nuclear remodeling and deacetylation complex), are thought to modulate transcription by influencing the status of chromatin remodeling. MTA1 overexpression is closely correlated with an aggressive course in several human carcinomas. Recent studies have shown that growth factor stimulation of breast cancer cells induces the expression of MTA1 and its interaction with and repression of the estrogen receptor (ER) transactivation function, leading to enhanced anchorage-independent growth in vitro and hormone independence. Furthermore, the status of the ER pathway modulates the expression of MTA3 as well as epithelial-to-mesenchymal transition in human breast tumors. MTA1 expression is not restricted to tumors; however, several normal mouse tissues and organs also express substantial levels of MTA1. Thus, MTA1 may play a role in both the physiologic and the pathologic states of cells. In Caenorhabditis elegans, MTA1-like genes regulate cell polarity, migration, embryonic patterning, and vulva development. In addition, two naturally occurring variants of MTA1, MTA1-ZG29p, and MTA1s have also been identified. ZG29p is an N-terminal truncated form of MTA1 and is present in the zymogen granules of the pancreas. In contrast, MTA1s is the C-terminal truncated form present in the cytoplasm. MTA1s binds and inhibits the nuclear functions of the ER by sequestering it to cytoplasm, stimulating the mitogen-activated protein kinase pathway. Furthermore, breast tumors with no or low ER in the nucleus exhibit elevated levels of MTA1s and cytoplasmic subcellular localization of the ER. This article reviews the current status of MTA biochemistry and its implications for tumor biology.
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PMID:Emerging roles of MTA family members in human cancers. 1461 24

Nuclear metastasis-associated 1(MTA1) protein is an estrogen receptor co-repressor that regulates transcription via chromatin remodeling, and MTA1 messenger ribonucleic acid (mRNA) levels are elevated in several kinds of locally advanced and metastatic tumors relative to non-metastatic tumors. Previous studies in our laboratory mapped MTA1 into a region showing significantly lower LOH (loss of heterozygosity) in primary breast cancers with metastases compared to node-negative tumors, suggesting that epigenetic alterations of MTA1 affect metastatic potential. The present study examined immunohistochemical expression of the MTA1 protein in treated and untreated primary human breast cancers to study the relationship between MTA1 expression and clinical outcome. Node-negative tumors that overexpress MTA1 protein had recurrence risks similar to node-positive tumors. In multivariate analysis of untreated node-negative tumors, highest expression of MTA1 was associated with increased relapse risk (hazard ratio (HR)=2.72, p=0.0003 for multivariate analysis). Tamoxifen and/or anthracylcene-based chemotherapies eliminated all MTA1 associations with clinical outcome, suggesting MTA1 overexpression predicts early disease relapse, but sensitizes breast tumors to systemic therapies.
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PMID:Breast tumors that overexpress nuclear metastasis-associated 1 (MTA1) protein have high recurrence risks but enhanced responses to systemic therapies. 1624 88

To distinguish aggressive esophageal squamous cell carcinoma from indolent disease is the important clinical challenge. Studies have indicated that metastasis-associated gene 1(Mta1) played a role in the process of metastasis of carcinoma. The overexpression of Mta1 gene has been found in a variety of tumors. To identify the detailed roles of MTA1 protein in the carcinogenesis of esophageal squamous cell carcinoma, this study analyzed the pathological specimens on tissue microarray derived from 72 patients using immunohistochemistry. MTA1 expression increased in the nuclear with the development of esophageal squamous cell carcinoma from normal epithelial cell, dysplasia, to invasive cancer. In biological studies with human esophageal squamous cell carcinoma cell line, MTA1 plays its roles to promote cancer cell invasion, adhesion and movement. RNA interference (RNAi) against MTA1 decreased the malignant phenotypes. Gene microarray analysis revealed some metastasis-associated genes were altered by MTA1 RNAi. This study started an effective beginning to explore metastasis mechanisms and cancer gene therapy strategy targeting MTA1.
Clin Exp Metastasis 2005
PMID:Reduced MTA1 expression by RNAi inhibits in vitro invasion and migration of esophageal squamous cell carcinoma cell line. 1670 14

Metastasis tumor-associated 1 short form (MTA1s) is a naturally occurring, alternatively spliced variant of MTA1 that functions as a repressor of estrogen receptor (ER) alpha transcriptional functions, at least in part by binding and sequestering ERalpha in the cytoplasm. A unique C-terminal 33-amino acid region containing a nuclear receptor (NR)-box motif (-LRILL-) mediates binding of MTA1s with ERalpha and is indispensable in this interaction. Here, we elucidated the solution structure of this 33-amino acid region by NMR spectroscopy. We found a predominance of the alpha-helical region toward the N-terminal region, which includes the NR-box motif. In silico docking and comparison studies showed similarities between the NR-box motif of MTA1s and a similar motif of coregulators, both in structure and mode of ERalpha binding. In MCF-7 breast cancer cells, the MTA1s peptide effectively repressed ERalpha transactivation function, as evidenced by the estrogen response element-luc assay and down-regulation of estrogen-induced genes. In mechanistic studies, we found that the antiestrogenic effects of the MTA1s peptide were due to its ability to compete with the coactivator recruitment to ERalpha. Furthermore, the peptide efficiently repressed estrogen-induced proliferation and anchorage-independent growth of MCF-7 cells. In addition, the MTA1s peptide blocked the progression of tumors formed by MCF-7 cells overexpressing an ERalpha coactivator in a xenograft-based assay. In brief, the characterization of structure and antiestrogenic activity of MTA1s peptide highlight its therapeutic potential.
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PMID:Solution structure and antiestrogenic activity of the unique C-terminal, NR-box motif-containing region of MTA1s. 1680 47

Nuclear receptors (NRs) rely on coregulators (coactivators and corepressors) to modulate the transcription of target genes. By interacting with nucleosome remodeling complexes, NR coactivators potentiate transcription, whereas corepressors inhibit transcription of the target genes. Metastasis-associated proteins (MTA) represent an emerging family of novel NR coregulators. In general, MTA family members form independent nucleosome remodeling and deacetylation (NuRD) complexes and repress the transcription of different genes by recruiting histone deacetylases onto their target genes. However, MTA1 also acts as a coactivator in a promoter-context dependent manner. Recent findings that repression of estrogen receptor transactivation functions by MTA1, MTA1s, and MTA2 and regulation of MTA3 by estrogen signaling have indicated the significance of these proteins in NR signaling. Here, we highlight the action of MTA proteins on NR signaling and their roles in pathophysiological conditions.
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PMID:MTA family of coregulators in nuclear receptor biology and pathology. 1817 18

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